interstitial cell of Cajal

These cells are derived from mesoderm,{{cite book|author=Kursad Turksen|title=Embryonic Stem Cell Protocols: Differentiation models|url=https://books.google.com/books?id=9Wk-5wuIR5gC&pg=PA263|access-date=14 April 2010|year=2006|publisher=Humana Press|isbn=978-1-58829-784-6|pages=263–}} unlike the enteric neurons that arise from neural crest cells.

Intramuscular Interstitial cells of Cajal (ICC-IM) are involved in mediating responses to neurotransmission.{{cite journal | author = Kito Y | title = The functional role of intramuscular interstitial cells of Cajal in the stomach | journal = J Smooth Muscle Res | volume = 47 | issue = 2 | pages = 47–53 | year = 2011 | pmid = 21757854 | doi = 10.1540/jsmr.47.47| doi-access = free }} All ICC in the gastrointestinal tract express calcium-activated chloride channels encoded by the gene ANO1. These channels are activated by release of calcium in ICC and are important for both the pacemaker activity of ICC and their responses to neurotransmitters. A recent review noted that carbachol increases ICC activity through this channel.{{cite journal |vauthors=Sanders KM, Zhu MH, Britton F, Koh SD, Ward SM | title = Anoctamins and gastrointestinal smooth muscle excitability | journal = Exp. Physiol. | volume = 97 | issue = 2 | pages = 200–206 |date=February 2012 | pmid = 22002868 | pmc = 3272164 | doi = 10.1113/expphysiol.2011.058248 }}{{cite journal |vauthors=Zhu MH, Sung IK, Zheng H, Sung TS, Britton FC, O'Driscoll K, Koh SD, Sanders KM | title = Muscarinic activation of Ca2+-activated Cl- current in interstitial cells of Cajal | journal = J. Physiol. | volume = 589 | issue = Pt 18 | pages = 4565–82 |date=September 2011 | pmid = 21768263 | pmc = 3208225 | doi = 10.1113/jphysiol.2011.211094 }} ANO1-knockout mice fail to produce slow waves and ANO1 channel inhibitors block slow waves.

ICC are also thought to be present in other types of smooth muscle tissues. But with few exceptions the function of these cells is not well understood and currently an area of active research.

ICC serve as electrical pacemakers and generate spontaneous electrical slow waves in the gastrointestinal (GI) tract. Electrical slow waves spread from ICC to smooth muscle cells and the resulting depolarization initiates calcium ion entry and contraction. Slow waves organize gut contractions into phasic contractions that are the basis for peristalsis and segmentation.{{medical citation needed|date=March 2014}}

The frequency of ICC pacemaker activity differs in different regions of the GI tract:Pocock, Richards, Richards, Human Physiology 4/ed, Oxford University Press, 2012. {{ISBN|978-0-19-957493-3}}. p.581

• 3 per minute in the stomach
• 11-12 per minute in the duodenum
• 8-9 per minute in the ileum
• 3-4 per minute in the colon

ICC also mediate neural input from enteric motor neurons. Animals lacking ICC have greatly reduced responses to the neurotransmitter acetylcholine, released from excitatory motor neurons, and to the transmitter nitric oxide, released from inhibitory motor neurons. Loss of ICC in disease, therefore, may interrupt normal neural control of gastrointestinal (GI) contractions and lead to functional GI disorders, such as irritable bowel syndrome.{{medical citation needed|date=March 2014}}

ICC also express mechano-sensitive mechanisms that cause these cells to respond to stretch. Stretching GI muscles can affect the resting potentials of ICC and affect the frequency of pacemaker activity. Carbachol increases ICC activity through ANO1 activation.

ICC are also critical in the propagation of electrical slow waves. ICC form a network through which slow wave activity can propagate. If this network is broken, then 2 regions of muscle will function independently.{{medical citation needed|date=March 2014}}

ICCs are thought to be the cells from which gastrointestinal stromal tumours (GISTs) arise.{{cite journal |vauthors=Miettinen M, Lasota J |title=Gastrointestinal stromal tumors: review on morphology, molecular pathology, prognosis, and differential diagnosis |journal=Arch Pathol Lab Med |volume=130 |issue=10 |pages=1466–78 |year=2006 |pmid=17090188 |doi=10.5858/2006-130-1466-GSTROM |issn=1543-2165}} Also, abnormalities in the ICC network is one cause of chronic intestinal pseudo-obstruction.{{cite journal |vauthors=De Giorgio R, Sarnelli G, Corinaldesi R, Stanghellini V |title=Advances in our understanding of the pathology of chronic intestinal pseudo-obstruction |journal=Gut |volume=53 |issue=11 |pages=1549–1552 |year=2004 |pmid=15479666 |doi=10.1136/gut.2004.043968 |pmc=1774265}} [http://gut.bmjjournals.com/cgi/content/full/53/11/1549 Full Text]

The interstitial cells of Cajal are named after Santiago Ramón y Cajal,{{cite journal |vauthors=Sanders K, Ward S |title=Interstitial cells of Cajal: a new perspective on smooth muscle function |journal=J Physiol |volume=576 |issue=Pt 3 |pages=721–726 |year=2006 |pmid=16873406 |doi=10.1113/jphysiol.2006.115279 |pmc=1890422}} a Spanish pathologist and Nobel laureate.

• List of human cell types derived from the germ layers
• Telocyte, a similar, and potentially equivalent, cell

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{{Gastrointestinal physiology}}

Category:Digestive system